VS Code Extension: Allow programmatic tab title/description updates

Problem

When working on multiple tasks in the VS Code extension, all tabs show the first message of the conversation as their title (e.g., "schau dir mal timeler an..."). This makes it hard to distinguish between tabs when working on different features or areas of a codebase.

Proposed Solution

Allow programmatic updates to the VS Code tab title/description, so users (and skills/hooks) can set meaningful names that reflect the current task.

Possible implementations:

1. CLI command: /set-tab-title "DATEV Export" or similar
2. Hook: on_task_change that updates the title automatically based on context
3. Skill support: Allow custom skills to update the tab title as part of their workflow
4. Auto-detection: Infer the task from the conversation and update the title automatically

Use Case

• Working on multiple features in parallel (e.g., "Invoice Export", "Booking System", "Dashboard")
• Using skills/journeys that focus on specific topics — the tab should reflect the active context
• Quickly identifying which tab contains which work stream without clicking through each one

Current Workaround

Manual rename via the "Past Conversations" dropdown → rename icon. This works but requires manual effort every time the task context changes.

Impact

Significantly improves tab overview and navigation when running multiple Claude Code sessions in VS Code.